Precision CNC from a single block of aluminum Anodized finish provides smooth flipping Compatible with any disc-binding system Sturdy and light weight Holds about 120 sheets of 80gsm paper or 80 sheets of 120gsm pape Discbound system is a wonderful invention. However, most of the off-the-shelf discbound notebooks come with only plastic discs. While they serve their purpose well enough, you deserve better. Aluminum discs make flipping the pages a breeze and they do not break when you accidentally drop it on the floor. Most importantly, they feel luxurious and look great!